I have actually cut with both methods achieving similar results. I have read the threads and they are extremely informative. I was just hoping that my particular situation with the machine cutting nice parallel key splines would have a logical place to start with my limited knowledge of more in depth troubleshooting of these machines. If you wouldn't mind maybe some tips on how you would check endplay and backlash of the index worm as you suggested in your reply. Also how would you remedy or adjust any faulty findings. I hope that I am not asking for too much but I would be a fool not to try to take advantage of your expertise. I really appreciate any info that you are willing share with me.Are 16-16s and #12s similar enough in design that I can use the previous threads and apply them to my situation?